I am a Chinese, I'm going to immigration to the United States. > I am a Chinese and I am going to immigrate to the United States.

I want to study well in English as soon as possible，what should I do?> I want to study English well as soon as possible. What should I do?

You can improve your English skills by practicing. You can study English in the U.S. Or you can get a language partner, community teacher or professional teacher here in italki to help you get started. It is also helpful to read English articles and books or watch Hollywood films too. Good luck!

I want to speak well in English as soon as possible; what should I do?"

My answer, as it has been for this sort of question, is to start speaking. Get English partners who want to learn Cantonese or Mandarin, get on Skype with them, and teach them one of your native languages in exchange for English practice. The more you speak it, the more comfortable you'll become, and when you do it with native speakers, they can correct you before you memorize something incorrectly.

Also, remove almost all forms of Mandarin or Cantonese media from your daily routine. Only speak/read those languages if you absolutely have to. Read all of your news in English, read all of your books in English, listen to all movies and tv shows in English, et cetera. Learning quickly is going to require somewhat painful immersion into the language; you can't afford to spend 95% of your week speaking Mandarin and only look at English when you're doing Skype practice. It's going to be awkward for a while, but immersing yourself in English media is very helpful for quickly developing fluency. Good luck!

In order to actually learn more English I suggest listening to as many songs in English as possible, watch movies in the language, talk with people online, etc. Since you speak Mandarin and Cantonese, it will be difficult to adjust the the more consonant-focused, front of the mouth, Germanic English language. I have many friends studying here at my university who did not know very much English before coming to America, and it's still quite difficult for them to get some of the grammar and structure down. Just practice as much as you can as often as you can. Immerse yourself in the language.